Scheduling decisions give rise to some of the most challenging optimization problems in the process industry. Formulating mathematical models for scheduling problems and devising tailored solution algorithms for these models has been the main thrust of previous literature. In this work, we focus on analyzing and resolving the cause of bottlenecks and infeasibilities in generic scheduling problems. We present a systematic approach for infeasibility diagnosis. Our approach exploits the known structure of scheduling models to isolate interpretable infeasible sets of constraints. We demonstrate the power of the algorithm on infeasible instances of the Westenberger–Kallrath multipurpose batch process modeled using a state-task network (STN) representation. The methodology presented in the paper is able to successfully analyze the cause of infeasibility and provide recommendations for resolving it. We also demonstrate how these insights and recommendations can be presented to scheduling operators with little or no optimization expertise in an intuitive manner.

调度决策会引起过程工业中一些最具挑战性的优化问题。制定用于调度问题的数学模型并为这些模型设计量身定制的求解算法一直是先前文献的主旨。在这项工作中，我们专注于分析和解决通用调度问题中瓶颈和不可行的原因。我们提出了一种不可行诊断的系统方法。我们的方法利用调度模型的已知结构来隔离可解释的不可行约束集。我们在使用状态任务网络（STN）表示模型的Westenberger-Kallrath多功能批处理的不可行实例上证明了该算法的强大功能。本文介绍的方法能够成功地分析不可行的原因，并为解决不可行提供建议。我们还将演示如何将这些见解和建议以直观的方式呈现给几乎没有优化专业知识或没有优化专业知识的调度操作员。